In electronic systems, such as computer systems, it is often necessary to provide a computer with a redundant power source. In some computer systems, such as those used in the telephone industry, when power supplies are connected to their associated computers, they receive, through a primary connection, a fixed DC voltage such as −48 V DC and control signals through a secondary connection. The power supplies also provide various rail voltages to the computers through the secondary connection. The connections are facilitated by primary and secondary connectors carried by the computer system chassis and the power supplies.
Generally, to connect and disconnect redundant power sources, two conditions must be met. First, one side of the primary connection and one side of the secondary connection must float in a plane perpendicular to the connection axis, in either the power supply or computer system chassis, to enable the corresponding connectors to pick up and engage with their mating connectors without positional in-fighting or snubbing. Secondly, the primary connection must electrically make first and break last.
This second condition, contemplates that in these applications, it is essential that the primary connection be made prior to the secondary connection. This enables the power supply to connect to the primary DC voltage source provided by the computer before it is turned on and begins generation of secondary rail voltages. Likewise, when the power supply is disconnected from the computer, it is essential that the control signals turn off the secondary rail voltages by breaking the secondary connection before the primary source power is lost by disconnection of the primary connections. This sequence requires a make first break last connection assembly.
The foregoing sequence must be held under all tolerance conditions for the proper operation of the system. The combined tolerances of both their primary and secondary connectors can result in considerable wiping action requirements of the primary power connector to ensure the make first break last requirement. The present invention provides a make first break last connection assembly which meets the wipe requirements and reliability tolerances required in such applications.